Apparatuses, systems and methods for tilling agricultural fields are very well known in the art. Apparatuses typically comprise a cultivator frame having multiple and various tilling attachments attached thereto, laid out on the frame in a variety of patterns to maximize the desired tilling effect. The apparatus is dragged behind a vehicle during the tilling operation.
In particular, conservation tillage, or vertical tillage as it is sometimes called, has recently become a tilling strategy of choice in many instances. Conservation tillage minimally disturbs the soil prior to planting in order to allow air to penetrate the mat of crop residue left in the field from the previous harvest. Apparatuses, systems and methods for conservation tillage are known in the art, for example United States patents U.S. Pat. No. 7,762,345 issued Jul. 27, 2010, U.S. Pat. No. 8,113,295 issued Feb. 14, 2012, U.S. Pat. No. 8,196,672 issue Jun. 12, 2012, U.S. Pat. No. 8,307,908 issued Nov. 13, 2012 and U.S. Pat. No. 8,307,909 issued Nov. 13, 2012, the entire contents of all of which are herein incorporated by reference.
In addition to coulter wheels, chisel plows, V-shaped shovels, sub-soiling teeth and other field working tools, a tillage apparatus may comprise leveling attachments at the rear of the cultivator frame. The leveling attachments may be mounted to a rear transverse cross-member of the frame. Leveling attachments may comprise, for example, spike or tine harrows, leveling bars, rotary harrows, etc., which are dragged behind the cultivator frame to level the field after the field is worked by the field working tools.
A conservation tillage apparatus may be drawn at faster speeds than conventional tillage apparatuses. Although there is no theoretical upper limit on speed, conservation tillage apparatuses may be operated at speeds of from 8-18 miles per hour. Operating at such faster speeds causes the crop residue to be cut more finely and reduces the likelihood of becoming stuck in wet soil conditions. However, operating at faster speeds, especially above 12 miles per hour, can create significant problems with leveling attachments being dragged behind the cultivator frame.
Harrows are implements (leveling attachments) comprising sets of teeth, tines or ridges that when dragged over ploughed land break up clods, remove weeds, and cover seed. A tine harrow is a harrow having a plurality of narrow profile tines or spikes downwardly depending from a harrow frame. The tines may be spaced apart transversely on the harrow frame to form a row, and a plurality of rows may be spaced apart longitudinally on the harrow frame to form an array of tines on the harrow frame. Two or more harrow frames may be mounted at the rear of the cultivator frame, usually forming a transverse row of tine harrows. Adjusting the angle of the harrow tines changes how aggressively the tines interact with the land by raising and lowering the ends of the tines with respect to the land. The desired aggressiveness of the harrow tines depends on land conditions, which may change from day-to-day, or even from place-to-place on the land. Angle adjustment of the tines is generally done collectively so that the angles of all of the tines on a given harrow frame, and indeed all of the tines on all the harrow frames mounted on the cultivator frame, are changed at the same time. A number of ways to accomplish such angle changes are known in the art, for example as described in U.S. Pat. No. 8,657,026 issued Feb. 25, 2014.
However, prior art apparatuses do not permit independent control of each tine or at least a single row of tines, which limits the effectiveness of the tine harrow in changing land conditions. There remains a need for ways of adjusting the position of individual tines or individual tine rows in one or more tine harrows in relation to a surface of the land.